Big Brother host Julie Chen teased there would be a "familiar face" among the season 15 cast announced Thursday – and it belongs to former contestant Rachel Reilly's sister Elissa Slater.

"I've always loved Big Brother and I've always wanted the opportunity to do it," Slater tells PEOPLE. "I hope people at home see that I am in it to win it and a force to be reckoned with."

Slater, 27, is one of 16 houseguests competing for the $500,000 prize during season 15 of the CBS reality show – the largest cast ever.

"Forming an alliance is my main strategy," says the nutritionist and yoga instructor. "I definitely want to form the first girl alliance in Big Brother history that will make it to the end. I'm such a girly girl and I think it would be really fun for girls to run the game."

Slater initially planned on keeping her relation to Reilly – a two-time competitor and winner of season 13 – a secret, but her sister had different advice.

"I was like, 'That is the dumbest plan because they are going to just think you are lying or trying to keep something from them,' " Reilly says. "Elissa and I look so similar that I think it is just obvious. I think she will end up telling people."

And while Slater calls Reilly her "favorite player because everyone underestimated her," she is not planning to play exactly like her sister.

"I want to have her competiveness and focus but I don't want to play her social game because that was bad," says Slater. "I want to be socially savvy."

Slater – who will spend the summer away from her son Riley, 8, as well as her husband Brent and his three children from a previous marriage – will be joined in the '60s-style Big Brother house by fifteen other house guests. Among them: political consultant Helen Kim, 37, who applied after three months of bed rest while suffering from MRSA infection; communications professor and improv actor Andy Herren, 26, who says he will be compared to season 12's Ragan Fox; and professional inline skater and entrepreneur Nick Uhas, 28, who describes himself as "super-energetic, which could be too much for people."

Big Brother invited members of press to step into the shoes of the houseguests they will report on all summer long. On Monday, June 17th, nine members participated in a day long mock competition of their own. This series of clips from press day 2013 demonstrates just how intense the Big Brother house can be, turning even the most consummate of professionals into cutthroat competitors vying not to be the person evicted!

"THE TALK" HOSTS MOVE INTO THE "BIG BROTHER" HOUSE FOR A SPECIAL SHOW TO AIR ON "THE TALK," WEDNESDAY, JUNE 26

Julie Chen and Co-Hosts Compete Against Each Other in the "Big Brother" House; See Which Host Gets Evicted LIVE on “The Talk”Plus, a Sneak Preview of the Upcoming Season of CBS’s Hit Summer Reality Series

Prior to the arrival of this season's BIG BROTHER Houseguests, the ladies of THE TALK moved into the BIG BROTHER house to compete against each other as part of a special BIG BROTHER preview show, to be broadcast on THE TALK, Wednesday, June 26 (2:00-3:00 PM, ET; 1:00-2:00 PM, PT) on the CBS Television Network. The new season of BIG BROTHER premieres that evening, 8:00-9:00 PM, ET/PT.

Inside the house, Julie Chen and co-hosts Sharon Osbourne, Sara Gilbert, Sheryl Underwood and Aisha Tyler spend an afternoon partaking in the full BIG BROTHER experience, playing an abbreviated version of the game. On Wednesday’s episode of THE TALK, the ladies will reveal which host was voted for eviction. Also, the show will feature a preview of this season’s BIG BROTHER.

Chen is co-host and moderator of THE TALK as well as the host of BIG BROTHER.

CBS’s THE TALK, daytime television’s fastest-growing network talk show, recently received three Daytime Emmy Awards, and was nominated for Outstanding Talk Show-Entertainment. THE TALK features a panel of well-known news and entertainment personalities who examine current events, pop culture, contemporary issues, family, celebrity and the trending topics of the day. The daily one-hour series is co-hosted by Julie Chen, Sara Gilbert, Sharon Osbourne, Aisha Tyler and Sheryl Underwood. The hosts swap stories, challenge each other on issues and engage the studio audience and viewers at home about events in the headlines and their own homes. Show segments include guest interviews with entertainers and newsmakers, musical performances, how-to demos and appearances from extraordinary people with stories that engage and inform. The show was developed by Gilbert, who also serves as executive producer.

BIG BROTHER follows a group of people living together in a house outfitted with 65 cameras and 98 microphones recording their every move 24 hours a day. Each week, the Houseguests will vote someone out of the house. At the end, the last remaining Houseguest will receive the grand prize of $500,000.

BIG BROTHER is executive produced by Emmy Award-winning producer Allison Grodner and Rich Meehan for Fly on the Wall Entertainment, in association with Endemol U.S.A.